Advances in genetic technology and biological understanding in the last 100 years have opened a new era of discovery and investigation. In the centennial year of the journal GENETICS, we quantify the remarkable shifts in genetic research through textual analysis of publications. We characterize changes in the focus of genetic research by studying all available abstracts and titles of papers published since 1916 in GENETICS. We document a massive expansion in publications in genetics, beginning in the 1950s, and accelerating in the 1980s, as genetic research expanded globally from a few initial locations. We also describe changes in word usage over time, reflecting evolving research interests, methods, and organisms. For example, we observe stable use of Drosophila in genetics research throughout the century. In contrast, we document rapid increases in human genetic research and extreme expansion in use of model organisms, including Escherichia coli, Arabidopsis thaliana, Caenorhabditis elegans, and Saccharomyces cerevisiae, and a later decline in use of prokaryotes. We use bibliometric analyses to measure the most prominent research trends as reflected in the journal GENETICS.